Nowadays, the need for new energy production and transfer related solutions is increasingly important. Electronic applications have a huge impact on our life. That is why it is also important to consider using sustainable approaches which allow reducing both greenhouse effect and carbon dioxide emissions.
The ability to produce energy from alternative sources such as sun, wind, wave motion and biomass allows for a significant reduction in environmental impact and polluting emissions compared to traditional energy sources based on fossil fuels. Solar energy, for example, can help developing countries or small mountain and rural communities to equip themselves with efficient, economical and virtually zero environmental impact plants for the production of electricity. Photovoltaic panels have undergone a rapid and significant evolution in recent years, offering users increasingly efficient and reliable solutions that require reduced maintenance and are able to produce energy even in conditions of low solar radiation. At the same time, the simplicity of installation has grown, favored by the introduction of flexible panels capable of adapting to surfaces of various types. Photovoltaic systems are normally combined with special units for storing the electricity produced, made with storage batteries more or less evolved according to the available budget. These batteries allow to accumulate energy during the day, and then make it available for lighting and powering different loads during the night. Not only that, they are also able to detect blackouts, automatically becoming the primary energy source in the event of a power failure. Unlike generators, storage batteries are able to deliver energy without the use of fuel and in a silent way.
Of equal importance to energy production is the transfer of energy, especially if this can take place wirelessly, without requiring the use of bulky and often annoying electrical cables. The wireless electricity transfer technique, based on the principle of electromagnetic induction, has returned to the fore in recent times thanks to two applications that have become priority. The first, relating to the consumer electronics sector, concerns the charging of battery-powered mobile devices (typically smartphones), which can be recharged simply by placing them on a suitable source capable of transferring electricity by conduction. The second main application concerns the recharging of batteries in electric and plug-in hybrid vehicles, carried out by means of devices that can be placed on the floor below the car or even integrated into the road surface. In addition to not requiring the connection of electrical cables, this solution proves to be very effective from a safety point of view, as it does not expose the user to the potential risk of contact with the high powers involved.
In the next paragraphs, two highly innovative real applications will be presented, relating to the exploitation of solar energy as a source of electricity and the transfer of wireless energy in various types of contexts.
Flexible solar PV
Power Roll, based in Sunderland (UK), has developed an innovative model of solar film capable of generating and storing energy. Lightweight and flexible, the solar film is able to adapt to any type of surface, producing electricity at a cost up to 20 times lower than traditional photovoltaic panels. The new technology is based on a flexible film patterned with thousands of microgrooves. Each microgroove is a few microns thick, smaller than a human hair.
The advantages offered by this solution are the following:
- low cost: 0.03 $/Watt for the finished product;
- low weight: 0.3 kg/m2;
- easy installation and reduction of maintenance times;
- sustainability, due to the use of fully recyclable materials and absence of rare earths;
- adaptability: the same technique can be used either on the roofs of buildings or for powering small IoT sensors;
- high power density: 500 Watt/Kg.
As shown in Figure 1
, the flexible film enables roll-to-roll manufacturing of capacitors using a range of dielectrics and storage materials. This capacitor technology, employed for storing energy, offers:
- ultra-low-cost manufacturing;
- exceptional energy density;
- multiple shapes and sizes with voltage and capacitance flexibility;
- enhanced operating lifetime compared with wet electrolytic capacitors.
The phases of the flexible solar film manufacturing process are outlined in Figure 1
Figure 1: manufacturing steps of a flexible solar PV
“Our technology has several advantages over flexible solar technology. It is extremely easy to produce. There are fewer steps in a manufacturing process,” said Neil Spann, Managing Director at Power Roll. He added, “If you look at flexible photovoltaics, we can say that it is much more expensive. So, in reality, the main advantage of our technology is cost-effectiveness. In terms of efficiency, our efficiency is good. But we don’t aim to make the highest performing solar panel in the world, there are some technologies that push the devices upwards. We are looking for a compromise, a good level of performance. So our current cell performance is 11%, which is somehow comparable to other flexible solar panels like organic photovoltaics. But we plan to increase it up to 20%. And thanks to the possibility of customization, there is a wide range of applications.”
By applying different active materials to Power Roll microgroove technology, it is possible to create energy storage solutions with a range of discharge times. Today’s solar technologies are either too expensive to deploy or their rigidity and weight makes them unsuitable for the job. Power Roll’s low-cost, flexible and lightweight solar film enables the use of renewables in brand new applications. In partnership with The Energy Resources Institute (TERI), Power Roll
is installing an innovative solar mini-grid system to generate and store energy in rural villages located in Mukteshwar, in the Himalaya, India. The system comprises lightweight, portable solar PV to generate energy and an energy storage capability to enable energy use at night. Each system has been designed to meet the bespoke needs of each village. Applications include powering water pumps to support irrigation, lights to help young people study at night and power to run phones enabling access to national and international knowledge and support networks. Through this project Power Roll is also experimenting novel approaches to mounting the solar film using wire tensioning systems, which allow the solar film to be quickly and easily moved to where it is most needed. The project is scheduled to run through to the end of 2021 and Power Roll will report on the outcomes in March 2022.
Wireless power transfer
PowerSphyr, a company with headquarters in Danville, California, aims to revolutionize power delivery to electronic devices via its intelligent wireless power technology
. PowerSphyr offers the following solutions to fit any application:
- Magnetic Resonance, a solution which offers high power delivery and spatial freedom. It is safe for nearby metals, offers an excellent thermal management and supports multiple devices simultaneously;
- Qi, the simplest and lowest cost solution. It features limited spatial freedom, power delivery and thermal management (metals become very hot). Moreover, this solution requires a precise alignment between transmitter and receiver;
- Capacitive, a solution suitable for industrial applications where very high power is demanded;
- RF Energy Harvesting, a great solution for sensors and IoT applications. It has excellent spatial freedom (up to 40 feet), can be used to harvest existing frequencies and supports FCC regulatory limits.
family of wireless power transmission and receiving solutions enable fast, easy-to-use, and secure wireless charging across a wide range of products and modules. Each product includes a fully developed reference design. Key markets of Skycurrent products include automotive, consumer and industrial. PowerSphyr designs wireless power products and modules for the automotive
industry that eliminate the need for cables or precise coil alignment, enabling fast, easy to use, and secure charging ecosystems with elegant industrial design and flexible form factors. Figure 2
shows an automotive application which includes wirelessly powered sensors for control and monitoring (lights, airbags, temperature, doors, etc.) and wireless charging for occupants’ devices supporting magnetic resonant, Qi and RF solutions.
“One of our goals is to reduce complexity by rethinking how the automotive cockpit is powered – wirelessly. This means removing connectors and replacing traditional methods with future-proof wireless solutions.
Many companies have focused on wireless power to charge mobile devices in the cabin but there is a substantial opportunity to streamline manufacturing, improve safety, reliability and reduce cost inside vehicles with PowerSphyr’s new generation of wireless power technology.
Vehicles today contain over two hundred connectors that provide power and communication to critical features and systems. As the electrification of vehicles continues to progress, we will see vehicles become more feature rich and increasingly dependent on software. A new approach to connectivity will become essential.
We also are seeing a massive increase in the amount of copper within vehicles. While most is related to batteries and propulsion, it is also used to direct energy throughout the vehicle,” said Will Wright, CEO at PowerSphyr.
He added, “instead of using wireless power to charge a phone or tablet, we are developing wireless solutions to reduce the complexity of wire harnesses and connectors. Whether it is powering seat motors, heated seats or side mirrors and speakers, a wireless approach solves many challenges the industry has faced for years.
PowerSphyr offers solutions from low power to 450 Watts and we are working every year to push our technology further for our customers in the automotive and industrial space.
Our primary technology is a proprietary form of magnetic resonance which delivers power at 6.78 or 13.56 megahertz, depending on the application. I cannot stress enough the importance of phenomenal electromagnetics design. Our new solutions provide both power and communication seamlessly.”
Figure 2: automotive application including wireless powered sensors and wireless chargers
Regarding the industrial
sector, PowerSphyr seamlessly supports the three primary standards for wireless charging (magnetic resonant, magnetic inductive and AirFuel RF), able to meet middle to high power demand of industrial tools and machinery. For the consumer
industry, PowerSphyr offers SkyCurrent III (shown in Figure 3
), the ultimate wireless charging platform delivering its dual-mode wireless charging pad and a suite of ‘fast charging’ battery cases.
This article was originally published on EEWeb.
Figure 3: phones charging on the SkyCurrent III device